This invention relates to a roving brake for retarding the movement of strands of fiber glass or other material therethrough.
Many structures are constructed by spraying a resin and chopped fiber glass roving simultaneously onto a work piece, by the use of a resin spray gun which carries a roving chopper thereon. In the use of the spray gun, fiber glass roving is rapidly removed from a box containing a large coil roving, and is guided along an overhead guideway on a boom that extends to the gun location, while the gun chopper rapidly chops the roving and sprays it out. The gun is often stopped and restarted. When the gun stops, the rapid moving roving continues to feed out of the coil for a large fraction of a second. As a result, large loops of free roving are created outside the box and at the spray gun. The loops often lie on a floor that may contain stray resin or other contaminants which can be picked up by the roving to later dirty or jam the cutter and harm the sprayed work piece. Also, it is found that the roving loop can form knots that jam on the guide waves and cause breakage of the roving when it is next pulled, requiring the operator to spend time to thread the roving through the guide ways and gun chopper. A simple device which could be easily mounted in place and which could minimize the feeding out of roving when the spray gun no longer pulls it, and yet which could freely feed out the roving when the spray gun began to pull it again, would facilitate the use of roving.